Ghost Light in the Attic - Pat Thomson

When Tom and Bridget come to Bridgeford Hall at first they think it might be haunted. And they are terrified when they see Elinor Bassingbourn step out of a seventeenth-century family portrait. But Elinor needs their help. So Tom and Bridget follow her back into her time to Civil War England, where even within a single family, loyalties are divided. Can the three children help Elinor's brother escape capture?